I don't mean to ruin your day, but your taxes are due tomorrow (Tuesday). Here are some tips for down-to-the-wire filers.
First, use the Internal Revenue Service's e-file system. It's fast, safe and will get you any refund quicker, which is always a good thing.
If you're mailing in your return, you can make sure you've got the right address by checking at www.irs.gov (click the "where to file" link). Your check should be payable to "United States Treasury" (not "that greedy so-and-so who keeps reaching into my pocket") and should include your Social Security Number to ensure that the right check is moving through the system with the right return.
If you're having trouble coming up with all the money the IRS wants, pay as much as you can to minimize penalties and interest. Then contact the agency about arranging a payment plan to make up the difference.